Twin-cylinder engine.



H. LEMP.

' TWIN CYLINDER ENGINE.

APPLICATION FILED NOV. 27. 1914.

1 ,246, 1 2 1 Patented Nov. 13, 1917.

\gitness 5: U Inventor":

Hermann Lem Hisa ttorne q.

jector 13 of any suitable type.

UNITED PT HERMANN LEMP, 0F ERIE, PENNSYLVANIA, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

TWIN-CYLINDER ENGINE.

Specification of Letters Patent;

Patented Nov. 13, 1917.

To all whom it may concern:

Be it known that I, HERMANN LEMP, a citizen of the United States,residing at Erie, county of Erie, State of Pennsylvania, have inventedcertain new and useful-Improvements in Twin-Cylinder Engines, of whichthe following is a specification.

The present invention relates to twin cylinder engines and moreespecially to those of the internal combustion two-cycle type operatingon the high compression plan wherein both pistons are operated from asingle crank on the main shaft.

In such arrangements one of the piston rods is connectedto the crank andthe other is connected to the first rod so that both move to ether.

Theo ject of my invention is to provide an. improved arrangement in anengine of the above mentioned type.

For a consideration of what I believe to be novel and my inventionattention is directed to the accompanying description and claimsappended thereto.-

In the drawing is shown a twin cylinder internal combustion engine invertical section.

The cylinders 1 and 2 are vertically disposed, although this is notanecessary feature of my invention. They are arranged in parallelrelation to each other and are connected at the top by a shallowcombustion chamber 3 so that combustion in both'cylinders takes placesimultaneously. The cylinder 1 is provided with one or more scavengingports 4 and cylinder 2 with one or more exhaust ports 5, the formerports being controlled by the trunk piston 6 and the latter by the trunkpiston -7. Surrounding the scavenging ports is a chamber 8 thatcommunicates with the receiver 9 by a vertical passage 10. Any suitablemeans may be provided for maintaining a suitable air pressure within thereceiver. The exhaust ports are connected to the exhaust conduit 11 by asuitable passage 12. Fuel is admitted to the center of the combustionchamber by an in- In the one shown fuel is delivered to the injector b apump and high pressure air injects the uel when the valve opens. Themanner and direction of injecting fuel is not material to the presentinvention.

14 indicates the main shaft that is supported in suitable bearings 15 ofwhich one is shown. The shaft has a crank 16. One of the pistons, as 7for example, is provided with a connecting rod 17, the upper end ofwhich is secured to the piston by the wrist to extend into thecombustion chamber for a short distance on their compression stroke soas to reduce the volumetriccapacity of the chamber to the end that thetemperature of the compressed air therein will be raised to a pointabove the ignition temperature of the fuel admitted by the injector.This is accomplished by making the outer ends of the pistons conformapproximately to the shape 8f the end portions of the combustion cham-In order to permit the successful use of a shearing pin, it is necessarythat the angular motion of the connecting rod on this pin be negligible.To accomplish this result I have found that the shearing pin should beso located with reference to the crank 16 and wrist pin 21 that when thepistons are symmetrically located at the inner or outer end of theirstrokes, the centers of the crank 16, shearing pin 22 and wrist pin 21are in line with each other, as shown by the dot-anddash line. Fromactual experience and practice, I'havefound that with this relationthere is substantially no angular motion around the shearing pin.

The direction of rotation of the shaft 14 in the arrangement shown isclockwise and due to this arrangement the piston 7 controlling the,exhaust ports 5 will lead the piston 6 controlling the scavenging ports4 as is desirable in this type of engine.

It will thus be seen that by my improved arrangement I obtain astructure which pro vides a common combustion chamber for the twocylinder-sand gives the desired lead of the one piston over the other;while at One combustion space thus insuring a very thorough scavengingof the cylinders and the combustion space.

In accordance with the provisions of the patent statutes, 1 havedescribed the prin-, ciple of operation of-my invention, together withthe apparatus which I now consider to represent the best embodimentthereof; but I desire to have it understood that the apparatus shown isonly illustrative, and that the invention can be carried out by othermeans.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is,-

In a high compression two-cycle oil engine, the combination of a pair ofsimilar cylinders arranged side by side in parallel relation, exhaustports formed in one cylinder wall, scavenging ports formed in the othercylinder wall, the ports being located in the same transverse plane, areceiver independent of the crank chamber that contains compressed airand communicates with the scavenging ports, a shallow combustion chamberwhich is common to both cylinders and into which the pistons extend ontheir compression stroke to highly compress and heat the air therein,the products of combustion and scavenging air flowing through thecylinders and chamber in series, a fuel injector located in thecombustion chamber and delivering fuel to the central part thereof, atrunk piston in each cylinder which controls its ports and has a wristpin, a crank shaft, a connecting rod which connects the wrist pin of onepiston with the crank on said shaft and has an ofiset near its innerend, a shearing pin supported by said ofi'set, said pin being located ina plane passing through the center of the crank and the center of thewrist pin of the second piston,',and a rod connectmg the shearing pinand the wrist pin of the second piston whereby the pistons movesimultaneously but one of the pistons opens the exhaust ports in advanceof the scavenging ports and closes them before said latter ports areclosed by the other piston.

In witness whereof, I have hereunto set my hand this twenty-fourth dayof November, 1914.

HERMANN LEMP.

Witnesses: v

Orro F. Pnnsson, Q, 'l. Fonom.

